Jerome Raupach <jraupach@intelcom.fr> writes:
> testdb=#SELECT DISTINCT table_2.f1, table_1.f2, '2000-08-22' AS
> testdb-#date FROM table_1, table_2 WHERE table_1.f1 = table_2.f1;
> ERROR: Unable to identify an ordering operator '<' for type 'unknown'
> Use an explicit ordering operator or modify the query
> Is it a bug ?
No, I don't think so. The system has no way to intuit what datatype
you consider '2000-08-22' to be.
SELECT DISTINCT table_2.f1, table_1.f2, '2000-08-22'::date ...
would work.
regards, tom lane